Using new analytical techniques, a research team in California has made the first atmospheric measurements of nitrogen trifluoride, which is thousands of times more effective at warming the atmosphere than an equal mass of carbon dioxide.
The amount of the gas in the atmosphere, which could not be detected using previous techniques, had been estimated at less than 1,200 metric tons in 2006. The new research shows the actual amount was 4,200 metric tons. In 2008, about 5,400 metric tons of the gas was in the atmosphere, a quantity that is increasing at about 11 percent per year.
"Accurately measuring small amounts of nitrogen trifluoride in air has proven to be a very difficult experimental problem, and we are very pleased to have succeeded in this effort," says Ray Weiss of the Scripps Institution of Oceanography, in La Jolla, California, who led the study.
The research will be published on 31 October 2008 in Geophysical Research Letters, a journal of the American Geophysical Union (AGU).
Emissions of nitrogen trifluoride were thought to be so low that the gas was not considered to be a significant potential contributor to global warming. It was not covered by the Kyoto Protocol, the 1997 agreement to reduce greenhouse gas emissions signed by 182 countries. The gas is 17,000 times more potent as a global warming agent than a similar mass of carbon dioxide. It survives in the atmosphere about five times longer than carbon dioxide. Current nitrogen trifluoride emissions, however, contribute only about 0.04 percent of the total global warming effect contributed by current human-produced carbon dioxide emissions.
Nitrogen trifluoride is one of several gases used during the manufacture of liquid crystal flat-panel displays, thin-film photovoltaic cells and microcircuits. Many industries have used the gas in recent years as an alternative to perfluorocarbons, which are also potent greenhouse gases, because it was believed that no more than 2 percent of the nitrogen trifluoride used in these processes escaped into the atmosphere.
The team at Scripps, a graduate school of the University of California at San Diego, analyzed air samples gathered over the past 30 years. The researchers worked under the auspices of the NASA-funded Advanced Global Atmospheric Gases Experiment (AGAGE) network of ground-based stations. The network was created in the 1970s in response to international concerns about chemicals depleting the ozone layer. It is supported by NASA as part of its congressional mandate to monitor ozone-depleting trace gases, many of which are also greenhouse gases. Air samples are collected at several stations around the world.
The Scripps team analyzed samples from coastal clean-air stations in California and in Tasmania, Australia for this study.The researchers found that concentrations of the gas rose from about
In response to the growing use of the gas and concerns that its emissions are not well known, scientists have recently recommended adding it to the list of greenhouse gases regulated by Kyoto.
"As is often the case in studying atmospheric emissions, this study shows a significant disagreement between 'bottom-up' emissions estimates and the actual emissions as determined by measuring their accumulation in the atmosphere," Weiss says. "From a climate perspective, there is a need to add nitrogen trifluoride to the suite of greenhouse gases whose production is inventoried and whose emissions are regulated under the Kyoto Protocol, thus providing meaningful incentives for its wise use."
Michael Prather, an atmospheric chemist at the University of California at Irvine, predicted earlier this year that based on the rapidly increasing use of nitrogen trifluoride, larger amounts of the gas would be found in the atmosphere. Prather says the new Scripps study provides the confirmation needed to establish reporting requirements for production and use of the gas."I'd say case closed. It is now shown to be an important greenhouse gas," says Prather, who was not involved with the Scripps study.
"Now we need to get hard numbers on how much is flowing through the system, from production to disposal."
More than 100 years of flooding and erosion in 1 event
28.03.2017 | Geological Society of America
Satellites reveal bird habitat loss in California
28.03.2017 | Duke University
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
28.03.2017 | Life Sciences
28.03.2017 | Information Technology
28.03.2017 | Physics and Astronomy